Sliding clutch



Dec. 30. 1924.

J. P. BALDWIN SLIDIIIG CLUTCH mea .my 22' 1918 4 .Shasta-Sheet.` .1

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A `"uwl Dec, 30, 1924.'. 1,521,588

' J. P. BALDWIN SLIDING CLUTCH i Filed July 22l 1918 4 shame 2 F .6 Hf.ffl-1 a' 7l d 5 5 3l 33 I 3/ 33 I 2 7 /z 7 N P ,L\

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J. P. BALDWIN sunnm CLUTCH led July 22 191s 4 Sheets-Sheet 5 Dec.30,1924. 1,521,588

J. P. BALDWIN smrmm cLuTcH Filed July 23, 191s. 4 shutssheet 4 'fIl////////" Lzventor l f ll/lneas :hina: Pielt'e Baldwin DI: il

Patented Dec. 30, 1924.

UNITED STATES PATENT OFFICE.

JAMES PIERCE BALDWIN', F LOS ANGELES, CALIFORNIA.

SLIDING- .Application filed July 252,

To all 'who/Ht it may concern.'

lle it known that l, .learns pinnen BALD- wiN, a citizen ot the UnitedStates, residing at Los Angeles, in the county ot `Los ngeles and StateCalifornia.,have invented a new and useful Sliding-Clutch, .ot which thefollowing is, a specification.

This invention relates tr running friction clutches adapted lor use asspring dani'pers on `automobiles and relates morev particularly to thattype ot damper which uses moving struts tor actuating the frictionmechanism.

It is distinguished from such running clutches as are designed forsubstantie. ly unyielding engagement; and in order to more clearlyde'lineits character, I have terined it a sliding clutch. It is entirely:foreign to stationary clutches which are clutches that 'l'iunctionequally in both directions of movenient.

I-Iereto'l'ore. when ruiming clutches, that is, clutchesI .functioningin but one direction of movement, and substantially unyielding in thisone direction, havel been used as spring danipers, it has been necessaryto provide delicate adjustn'ients or to lit such clutches with resilientmembers, so that the clutch will oil'er the desired yielding resistance;and an objectot this invention is to so construct a running frictionclutch that it will oli'er the desired yielding resistance to movementof the spring, without the use of such resilient members and withoutdelicate adjustments.

Other objects. advantages and tea-tures ot invention will appear fromthe accompany ing drawings, the subjoined detailed description andappended claims.

I have illustrated in the drawings forining a` part of this application,the type of clutch en'iploying an annular ring and curved friction brakeshoes; but my invention applies to all types oil sliding clutchesemploying moving strut actuating means.

In the drawings, Figs. ll, 2, 3 and 4 serve to illustrate two methods olattaching the device to an automobile. f

Fig. is an enlarged t 'a-gniental eleva-tion ot the clutch shown in Fig.3, a. portion oi' the case being omitted to expose the interiorconstruction.

Fig. G is a section on line teef), Fig. 5.

Fig. 7 is a` fragn'lental diagrauiniatic view, on a greatly enlargedscale, oir one ot niy CLUTCH.

1.918.A Serial No. 246,498.

improved moving struts and some of the parts'coope" t' A therewith asshown in nig. 5. Construction lines are shown which serve to illustratea simple method of laying out the curvesvtor the contact faces oftheiniproved strut in such a. manner as to satisfactorily accomplish thepurpose of this invention. rlhe strut is here illustra-ted `being in theesiti-eine released position; that 1s, in Contact with the resilientrelease stop shown in Fig.

l Fig. 8 is a view analogous to i' showingv the equiif'alent position oithe parts when the struts arein a fully engaged position as indicated inFig. 5. In Figs. 7 and 8 an einigt/rated -1 )arisen of the released orinoperative position with the eng/a0' d or operative position, is made.F eathered and plain arrows respectively illustrate the clutching andreleasing movementsr of the y annulus.

Fig. 9 is a` fi'aginental diagrammatic de.- velopinent ot the contactlines ot shoe and strut at the outer end and ot abutment and sti-.it atthe inner end of the strut diagrarnnied in F i', showing the relativepositions oiE the contacting lines at the outer and inner ends oi' thestrut in the released position of Fig. 7.

l() is a view analogous to Fig. 9, showing the relative positions otlthe contacting lines of the strut. shoe and abutment when the parts arein the operative position ascribed to Fig. 8. ln Figs. 9 and l0 thecontact lines c, (l, e, f, ot the shoe and the outer end ot the strut.and oll the abutment and the inner end ot the strut, are shown asthough the elements were separated and turned'over to espose thecont-acting lines in parallelism with each other, so that the relativeshittingol the contacting lines at top and bottoni or the strut imposedby engaging and releasing and o v chang .s in the friction faces throfri wear and compression, inav be noted in l0 when coinpared to Fig. 9.

Fig. ll is a view ot a torni ot the inven- ,tion wherein the angle otthrust isvgreater than in the torni shown in the preceding views, thusproducing` less trictional resistance between the brake sho-es and theannulus. In this view. the involntc faces extend only throughout the:surfaces -iapted Vfor articulation and for compensation for wear andcompression.

lill) lll) Fig. 12 is a` view of a non-compensating form in which theangle ot thrust is not substantially constant but in which this angle isprevented from approximating Zero in relation to a normal to the brakeface, by means of a. stop with which the strutcontacts.

Referring to the drawings in det-ail; the base 1 in Figs. and 6, isadapted for attachment to one of the yieldingly separated members 2, 3,of the chassis by means of the bolts 44. The annulus 5 is journaledbetween the base and the cover-plate 22V by means of the extensions 6and 7 ot the annulus. 66 is a iinish ring pressed onto extension 6. Saidannulus is provided with an arm 8 adapted for attachment by a pin 9 anda connecting rod 10 with a clip 11 by which the arm may be connected toa body that is the complement ot' the body to which the base 1 isattached. The spring 12 is connected to the chassis 2 by any suitablemeans as by a `ioint 13 in the usual way. The base is provided with wayshaving side walls 14 and 15 parallel to a center line radiating from thecenter of revolution. ()ne of the side Walls olf each way is enlarged toform a post which is provided with a threaded hole 16 Jfor theattachniient ot the cover-plate 22 on the outer side by screws 4,

and the attachment of the base to the vehicle on the inner side by bolts44.

Adjustable floating strut abutments 17 are provided for the inner endsof thc ways and are adapted to move therealong when acted upon by thetriangular shaped eX- panding block 1S having three tapered fiat sidesand which is provided with a centrally threaded orifice 19 to receivethe adjusting screw 20 that has a head 21 outside the cover-plate member22; the expanding block being subject to the pressui'e of the spring 23which serves to maintain a snug contact between the working parts.

Brake shoe beams 24 having` metal backings 25 and facings 26 of leatheror other suitable material for engaging the inner wall of the annulus 5are provided with re cessed seats 27 to accommodate the outer ends otthe non-resilient struts the inner ends of which are accommodated by companion recessed seats 29 in the abutments 17.

In the preferred form, the struts are ot rigid relatively thin material,and the length of the strut is approximately equal to three andone-haltl times its thickness; that is to say, the distance between thebearing point-s on the respective ends of the strut is approximately notless than three and one-half times the length of the chord subtendingthe cam fared or curved strut ends. The radii for said curves are soproportioned that no projection of either ott said, curves will form aclosed curve with the other of said curves. The contacting lines 33 and34 of the strut are on opposite sides of the radial lines o, b and 0,b', which pass through the center of the strut at /J and c. In order topro-duce a substantially uncllanging angle of thrust, the bearingsurfaces must be of such curvature that the length ot the succeedingradii between the simultaneously contacting lines o'lI the strut, mustincrease or decrease according to the direction oi movement of thestrut, and must increase o-r decrease in length in direct proportion tothe magnitude oit such movement; that is to say, for each increment et'movement, for example, ten one-tliousandths ot an inch in the movingstrut, there must be a proportionate increment, say, one-thousandth kofan inch of separation or of approach between the parts that separated bythe moving strut. In laying out my struts, I therefore use substantiallyinvolute curves 3() and 31, developed irom a predetermined circle 32 fordetermining the proper curvature of the ends of my struts; but othercurves or combinations may be used to arrive at this result and wouldcome within the purview of this invention. In other words, various formsof cam iaces may be so constructed with relation to the required lengthot moving strut, or to the planes or curves on which such tacesarticulate, or to both the requisite length and such planes or curves,whereby the n'iathematical equivalent oi an involute tace articulatingon a dat surface may be rmidily obtained. Owing to the very limitedoscillation oit the moving struts in the form of device shown in thedrawings, the actual arcs ot articulation are very short; and thereforeit is possible to obtain substantially the same mathematical andmechanical results by curving the articulating portions of the ends ofthe struts in other Ways provided the objects of the invention arerealized. In other Words, When true in volute curves are used for thebearing ends ot.' the struts, the contacting arcs of such ends are sominute in extent that there is practically no difference in the .lengthoit the radi i. Ytor the respective ends ot such minute contractingarcs.

'lhus while it is oi advantage to use involutes, iiiarticularly inlaying out a certain construction of strut to meet certain requirements;it is practicable, by employing other arcs oi the proper degree o'fcurvature, to construct struts with ends which Will correspond soclosely to true involutes, in so tar as the actual contacting arcs areconcerned. that they will function substantially in the same manner asit' the entire ends had been constructed to conform to the predeterminedinvolutes indicated by the layout for the actual contacting arcs. It isnot necessary to have both ends oi the strut pr vided with substantiallyinvolute curves;

and an object of this invention may be attained by ang.v such acombination of curves as Will produce asubstantiall)Y constant angle ofthrust.

For example, a strut with a circular curve at the outer end andarticulating in a circular rec-ess m in the shoe, as slioivn in Fig. l2,may be provded with an articulation p, at the inner end that will servesome of the purposes of this invention.

In Figs. 7 and S, the projected lines 7L f/ (i and t g a drawn throughthe contacting lines 83 and 34 of the strut with its seats, indicato therespective lines of thrust through the strut for they tivo positionsshown, While the liiies 0 o (Fig. 7) and 0 o (Fig. 8) are normals to thefriction surface of the annnlus 5, drawn to intersect at L and a', theprojected lines 7L o and L a. respectively at said friction surface ofannulus 5. The angles 0 a and 0 a L thus formed. may be taken torepresent the angles of thrust for the two positions; and it uill benoted that the angles 0 o ,71y and o fr. it. are substantiall)Y thesaine. Lilie- 1e -n Fig. ll, the angles o i 7i and o a l /i .similarlyformed, are substant'allv the same.

For the purpose of this invention the angle of thrust herein referred tois defined as the angle occurring between a plane as (i 7i, Fig. 7.extending through the contact points and 34 and projected to intersectthc rub face of the friction. element or annuhis 5 and a line, as 0 fi.,drawn normal to said rub face from such point of intersection. The point0 is considered to be the center ot the annulns 5.

Thereis another angular force which l have indicated in Fig. 7 by abroken line drawn from P to P, the effect of which is negligible with astrut of comparatively thin proportions, but which is readil)7noticeable when the thickness of the strut inateriallyv exceeds theproportions noted above. This force P P is produced by contact of thediagonally disposed edges of the struts With the corresponding sides f/of the strut seats; and its effect is to slightl)v increase the angle ofthrust indicated by 0 fr i, and o ai 71,. lhen struts are made .vfth asubstantially greater thickness than the proportions noted. the effect.of the force l) P is to increase the indicated angle of thrust to snclian extent as to cause the struts to fail to function except when theclutch is poorly lubricated, or to be too slow .in functioning toproduce the most effective results.

I have found that, in order to regulate the desired resistance tomovement in the clutch lijf controlling the angle of thrust through the.struts, the struts must lie constructed with due relation to theco-etiicient, or angle, of friction between the annulus and the lnakeslices; that is to say. the angle of thrust in the strut should bearclose relationship to the angle of friction. For leather friction facingand ordinary cup grease for lubrication, a strut having' a greater angleof thrust than indicated in Fig. ll would be inoperative under certainunfavorable conditions such as increased flow of lubrication underrising temperature. On the other hand, if it is desired to increase thelresistance in the clutch, this ina7 be accomplished Without changes inlubrication or friction materials by employing' a strut with a smallerangle of thrust, such as is indicated in Fig. 7.

In Fig. i9, `the projected broken lines /r n1 and o i correspond tosimilar lines in Figs. 7, 8 and ll and the angle i o o indicates theangle of thrust when tne strut in full); engaged position. It will beseen that it is thus possible to predetermine the angle of thrust at theposition where the strut is ei;- erting its maximum pre nre. and with astyle of strut as at 2S 'l pror to my invention; and that this isaccomplished bj; arranging the Ways having side walls at one side of andparallel to a radial line, 0 s; and by thus providing a iixed stop at ifor preventing the strut from assuming a i.iosition in which the angleof thrust would an rc ia c the an e of Zero. virile this struc will J i'requisite yielding. it is not definable as the other forms illustratedYn that a comp; "ly long string of the strut to the lei't from theposition shon'n in Fig. l2 is required to effect free release in thedirection of free-niovcgs behind ting, or angular disposition of thecinved Ut ends relative to the axis of the struts. shown in Figs. i', 8and ll, the struts will be out of equilibrium in an)v position theirr.-'nirv suine vithin the space allowed for oscillation. B v reason ofthe unstable equilibrium U5 features thus provided. the struts will falllia-cl: into an iiioilieratire position as soon as the rotation of theann'ulus in the operative direction ceases: therebj.v relieving thevehicle springs of the damping etiect produ by the clutch, andelii'i'iinating the po, bilityv of the springs being bound down in acompressed position by the clutch.

lt r-:ill be noted that the construction of in v strut is such thatmaximum elongiition or maximum shortening of the space betn'een thecontacting lines will occur with but slight movement of the strut. iththe strut shown in Fig. ll, the oscillation will average about. one-halfof one degree. With No till tif)

the Strut shown. inFig. 7 the movement is but slightly more. The limitedoscillation thus produced has been found highly advantageous in that itimparts an almost instantaneous engaging and releasingaction, therebyminimizing wear as well as doing away. with lost motion, thus enablingthe clutch to properly damp the simili vibra tions of the springsuspension which heretofore have been very annoying. lt will also benoted that the tendency of my improved st-rut as shown in Figsl, S and11, is to roll alongthe flat articulating -au'faces of the shoe 24 andthe abutment 17, rather than toA rub or slide as would he the case ifconcave articulating seats are used as with the form illustrated in Fig.l2. 'l'his rolling action. greatly minimizes wear and is therefore ofimpi'irtance in that the life of the strut and the parts with which itcontacts is prolonged.

In Fig. 5, which shows the struts in cn- `@aged position, it will benoted that thc struts are not in contact with positive stops such ashave heretofore been necessary in clutches of this general class forgoverning the maximum swing of the struts and controlling the maximumsepiiiration of the shoe and support.

The elimination of the tired stops is of advantage in several ways. ltallows the struts to compensate for conside 'able wear without thenecessity of manual adjustments by means of the adjusting holt 2th andprevents an accumulation of lubricant on the friction surfaces byallowingl the strut to sufficiently tighten to squeeze out any.f-'urplus luln'icant from between thc friction surfaces.

There is a tendency of the co-etficient of sliding friction to increasewith pressure; such tendency varies more or less with the character ofthe frictional material and lubricant used. Vith combinations prod ucinga relatively rapid increase of frictional (fo-efficient with increasedpressure, it is advantageous to use contacting faces for thc struts socurved as to produce a slightly in creasing angle of thrust as thestruts straighten with rotation of the annulus in the operativedirection. My experience has been that, with suitable friction materialand lubrication, the variation thus occurring in the co-efticient ofslidingl friction is not. sufficient to require a great variation in theangle of thrust in order to prevent positive locking when the clutch isused as a spring damper. A close examination of the angles e h and 0 a hin Figs. 7. S and ll will disclose that, while in each case the anglesare substantially the same, the angle 0 e 7L is slightly greater than 0a z.. My experience is that this slight increase which. in this case isdue to the changing angle of the seat 27 in the shoe 24, is sufficientto prevent positive locking due to'increase in said co-etticient whenthe clutch is provided with suitable lubrication. If it is desirable touse but a scanty lubrication or a combination producingl a greaterincrease of frictional cortitcient lwith increase of pressure; then, inorder to obviate the possibility of the increasing co-eticient causingpositive locking, it is advisable to depart somewhat from asubstantially constant angle for the application of pressure, and to soshape the struts that the angles grow greater and the rate of separationbetween the support and the shoe increased more rapidly as the strutsmore in the pressure producing direction.

lVhile I do not confine the inoven'ients of my strut to positive limitsby moans of positive Stops arranged for that purpose, l do, however,provide the pads and titi which may be made of felt, soft leather orsome other suitable resilient material which serves to act as a sounddeadener as the struts strike the sides of the ways. .It is seldom thatsufficient looseness occurs iu the clutch to allow the struts to strikethe pads 36 in the pressure producing movement; but on the reversemovemem', the frictional drag between the annulus and the shoe will,even after the operative pressure has been relieved, cause the shoe tocling to the ring until the strut meets with some obstruction; and it.is advantageous to provide means to check this movement of the strutwithout producing noise.

.lt will be noted that my invention does not depend on resilient membersto insure proper yielding. As shown in the drawings the struts are ofrigid construction; there are no springs in the brake shoes, and theshoes themselves closely parallel the curvature of the annulus. Thefriction leathers are preferably made from compressed sole leather,formed to the exact curvature of the annulus, and the pressure incidentto use of such leathers in the clutch soon hardens them beyond the pointwhere the resiliency of the leather could affect the working of theclutch. In fact, in this construction, resiliency is an undesirablefeature, owing to the tendency of such resiliency to act in the natureof a. soft pad in which the strut would tend to bury itself; thereby, ina measure, destroying the desirable unstable equilibrium feature of thisstrut. Y

The spacing between the friction facings Q6 is not for the purpose ofimpartingresiliency to the brake Shoes, but is required in order toprevent chattering which would occur in use, if the friction facingcovered the entire shoe; and the space, as shown` is no greater thanexperience has indicated to be necessary for that purpose. This spacingalso facilitates the application of the facings tothe shoes, allows fora freer distribu tion of lubrication and for a readier coniii formanceof the acings to the curvature ot the annulus, lffhile such spacing i,crease the possibility of doilecting the alie shoes by great pressure,such deflection does not occur under the pressures requisite properspring damping where my sliding clutch is used as a shock absorber. Itis recognized that it might be possible to distort the annulus by theapplic tion olf unevenly distributed inte 'nal iessui'eg but suchvpossibilities ot de'tl tion and distortion are not suiicient to supplysuoli` resiliency as would cause the clutch o stier the pred" terminedyielding resis to n'iovement; and such resiliency as migl t thus occurdoes not come within the meaning oic this invention.

It will be seen that the strut is in the nature o't a shore or prop andthat, by this invention, I provide a construction in a sliding clutchusing moving' strut actuating means whereby the sticas on the strut islimited by the angle of the `toi-ces through the strut g. so that, whenthe predetermined stress is reached in the operation ot the clutch, thecontinued tendency `to operate the clutch is not elective to increasethe stress.

This invention differs from the prior1 art in that, I have constructed asliding clutch without the use ot resilient devices., the resistance tomovement in such clutch is liniited by controlling the direction offorces through the actuating means, and the pressure on the brake faceof the clutch is relieved upon cessation of movement ot the actuatingmeans.

I claim:

l. A shock absorber comprising a support, a member having a contactYface movable relativelyT to the support, means to limit the width otthe space between the contact face of said member and the support, acontact element engaging said contact tace, and a. non-circular movingstrut adapted and arranged to hold the contact element in contact withsuch face; said strut being supported at one end by said support andhaving rolling contact thereon and with the contact element. the twolines oi" contact at the inner and outer ends oi the strut,respectively, lying at all times in a plane, which plane, in all ot itssuccessive positions, makes substantially the same angle with theContact face of said member` and being adapted to produce pressurebetween the contact face and the contact element upon movement of theface in one direction relative to the support, and to relieve suchpressure upon movement in the other direction..

2. A shock absorber comprising a support, a member having a contact tacemovable relative to the support; means to limit the Width of the spacebetween the contact face and the` support; contact element engaging suchcontati' tace; and a non-circular moving ed to hold the Contact elementin with euch tace: said strut being supat one end b v saidL support andbeing l arranged to apply varying de- `sure upon the contact element,tially the same angle ot thrust.

53. A. shockv absorber comprising a support, a niemeer having a contactYlace movable relative to the sipport` means to limit the width olf thesp '3e between the contact face and the support, a Contact elementengaging the contact tace and a moving strut adapted to continually holdthe contact element in contact .vith the contact tace; sa id strut beingsupported. one end by said support and being constructed and arranged toapply pressure between the contact face and the contact element duringmovement ot the contact tace .in one direction and to relieve suchpressure upon cessation of such movenient.

4. In a shock absorber, in combination,

latively movable but non-separable members con'iprisinp; a base andfriction member, anda friction device tor producingpressure to effectthe requisite trictional resistance on one ot the relative frictionmembers, said device con'iprising a non-circular friction pawlconstructed and arranged to operate between said base and the other olisaid relatively movable parts at a substantially constant angle ofthrust throughout the space provided tor movement of said pawl.

5, In a shock absorber comprising an annulus, a shoe and a support, amoving strut arranged between the support and; the shoe and havingrolling` contact with both oi' these menibers. the lines otl contact atthe inner and outer ends ot' the strut, respectively, lying' at alltimes in a plane, which plane, in all its successive positions, makes aconstant angle with normals to the annulus from the lines ofintersection of' said plane with the annulus.

6. The combination with an annulus, a floating shoe contacting therewithand a support, of a wear compensating cam-faced moving strut operatingbetween said support and floating shoe; said strut being supplied withsubstantially involute contact faces.

'7. In a shocl absorber, the combination with an annulus, a floatingshoe contacting therewith and a support, of. non-resilient wearcompensating means operating between said support and floating shoe 3Asaid means consisting ot' a cam 'faced moving strut having substantiallyinvolute bearing faces and adapted to compensate for wear.

8. In a shock absorber, the combination with an annulus, a floating shoeand a support, of a cam faced moving strut operating between saidsupport 1nd floating shoe for at sebste producing pressure betiveen theannulns and the shoer` said strut li cinrg supplied with substantiallyinvolnte bearingl faces.

9. A. shock absorber comprising' two relatively movable frictionalelements, a support, a strut between the snpi'iort and one of saidelements 'to produce friction to .vieldingly resist movement in onedirection and to release upon reverse relative inovenient; andresilient' stops at the sides of the strut.

10. A. shock abiliorbcr coniprisingl an iuner support and an outerannclns harina' an internal friction face. a brake shoe ich face. and an'io'ving' strut centactiunl with said inner support and said brakeshoe.` thi` coiitactiniil surfaces of said strut being; so designed thatthe conta :t point between said strut and the support, ivien thi` strutis transmitting niaxinnun thrust.y is at one side of the radins norn'ialto the brake face and the friction face of the imonline which rad-ins isdraivn to pass through the point o f intersection of the friction-alface of the au nnlns with a projection of a line connectiney therespective contactingv points on the ends of the strut.

y ll.. A shock absorber comprising an inner support and an outer annulushaving4 an in ternal friction face. a brake shoe for such face, and amoving;l strut contacting; with said inner support and said brake shoe:the contacting surfaces of said strut ig-cina' so designed that thecontact point het vveen said strut and the brake shoe. when the strut istransniittingii'iaxii'nuin tlirush is at. one sil o f the radins nornialto the brutte the fric-.tional face of the annuo dius being' drawn tothe point ot intorwc rtion of the frictional face of the annulus with aprojection of a line connecting the respective bearingq points on tln`ends of the struts.

' 1 2. In a shock absorber` the combination with an annnlus and acentral supi'iort7 of a frictional surface in operative relation to theinside of the annulns, and a friction pawl and nieans whereby said pav'l.is set to operate at a substantially constant predc'ter inincd anglo oftln'ust` the panf'l beine' in coi'istant engagement with said means andsaid support.

In a shock absorber. the einnbii'iation with an annnlns and a centralsnil'nkiort. of a norfresilient frictional element in operative relationto the inside of tl f a inulus and a non-resilient friction paivlcontacting with the friction elen'ient. said parel being con structedand set to operate at a substantiall),v constant angle of thrust,substantially .is described.

14. A shock absorber con'iprisingg' a snpport; a brake device having'smooth rub facer` a device ha ving' a. friction face to engage said rubface; and means for producing pressure to effect frictional resistancebetween said devices: said nieans comprising a inoving strut set tooperate at a predetermined angle of thrust; said angle of thrust being'substantially the saine as the angle of friction between the rnb faceand the frietion face. v

lo. lfn a shock al'isorber the con'ibination with shore struts. cit abase having' radial Ways. an annnlus siufreuiiding.T the wars androtatable relative to the base. bralfe shoes engaging' the annnlns andprovided with notches to accon'nnodate the outer ends of the struts andabntnients in said Ways; said abutincnts having` notche.' arraiig'ed as'couipanions to those of the brake shoes respectively to accommodate theinner ends of said struts; there being a strut seat formed by each.notch: the bearing point for the strut in the seat of each brale shoebeing on one side. and the bearing point for the strut in the seat ofthe companion abutment being on the other side of a line drawn radial tothe base and the annulns and passing through the center of the strut;said struts lgieinn' in the Ways respectivel)T and having their endsseated in said seats.

ttl. ln a shock absorber, relatively niovable friction parts` a base anda support; operative ineans consisting' of a nonwirc'uhi r nioviira'strut having' pairs of bearing lines angularlv disposed relative to alongitudinal median line througl'i the strut` and being constructed andarranged to inodnce p. sure at a substantialli7 constant angle thrust.

lT. lln a shock absorber of the charinter set forth., a moving' struthaving substair tially involnte lieariup:

Y Vraces u'ith the hinh points o t said faces located on opposite sidesof a median line drun'n through the ends of the strut.

lS. In a shock absorber of the character set forth. a nioviuo strut`having' curved contact faces, the curves of said faces being angularlydisposed to. and with the high points on opposite sides of. a medianline through the strut and being constructed and arranged to applypressure at a substantially constant angle of thrust and relativelyinorable but uon-sep:nalile elements upon which the thr st of the strutis applied.

19. In a shock al'isorber of the character set forth, a moving; struthaving' curved conta-ct faces. the curves of said faces beV ing`produced froi'n ditferent centers located respectively on opposite sidesof a line in the saule plane with the curvesv and substantial lr in thecenter of the strut; the radii for said curves being' of such lengthsthat the proiection of the curve for one of said faces Will not forno aclosed curve with the other of said faces` and relatively movableelements between and upon which the thrust of the strut is applied.

it il 'joel 20. In a shock absorber con'iprising an annulus and risingmoving strut actuating means, a strut constructed and arranged with thein-ner and outer contact poi-nts for the ends thereof lying on oppositesides of a line drawn normalto the annulus and passing througl'i the.center ofsaid strut; throughout the allowable movement of the strut,andf relatively movable faces between and ou` which. the strut operates;said strut opera-ting at a substantially constant angle of thrust, saidangle beingA substantiallv equal to the angle ofv friction for thefrictional faces of said clutch.

2l. A shock absorber comprising an inner support and' an outer annulushaving an internal frictional face, a brake shoe for such face. and amoving strut. contacting with said inner support and said brake shoe:the contact point between sa-id strut and the support and the contact:point between said strut and the bra-ke shoe, when both the outer andinner points have reached a position of `maximum effectiveness. being onopposite sides of aline dra-wn normal to the brake face and passingthrough the center of said strut: the angle of thrust for said strut,when such position of maximum effectiveness has been reached, beingsubstantially equal to the angle of static friction between saidinternal1 face and said brake shoe.

22. A shock absorber comprising an annular ring and' a floating shoecontacting therewith and a support and means for creating an outwardradial movement of said shoe and consequent frictional resistancebetween the shoe and the ring, said means being constructed andIarranged with successive pairs of contactingr lines for the bearing endsthereof, said pairs lying in successive planes angularly disposed inrelation to normals to said ring, said normals being drawn to the pointsof intersection of projections of said pla-nes with said ring, the anglebetween said normals and said planes remainingr constant with furthercircumferential movement of the shoes as they tend to follow the ring.

23. In a shock absorber, the combination with an element constituting anannular shell; of a radially slotted, centrally chambered base;non-resilient shoes to engage the shell; a triangularly shaped memberhaving flat tapered sides in the central chamber of the base; abutmentsin the slots; and nonresilient moving strut means between the abutmentsand the shoes; said base being provided with lugs; and stops retained bysaid lugs for limiting the movement of the moving strut means.

24. In a shock absorber adapted to control the reaction of vehiclesprings and comprising a brake face` a rub face and a support the brakeface and support being non-separable; non-circular friction pawlconstructed and arranged to produce pressure between said faces at asubstantially constant angle of thrust.

In a shock absorber, the combination` with movi-ng struts, of a basehaving radial ways, supports for the struts, abutments for the supports,an annulus surroundingt-he ways and rotatable relative to the fays,means to regulate the space between the annulus and the support-s, andbrake shoes engaging the annulus; said shoes and supports beingfittedwith flat articulating surfaces for the bearing ends of' the saidstruts. i

QG. In a shock absorber, the combination with movingstruts; of a basehaving radial ways. supports for the struts, an abutment for thesupports, an annulus surrounding the ways. means to regulate the spacebetween the annulus and the supports, and brake shoes engaging theannulus; said supports being fitted with flat articulating surfaces forthe inner ends of the struts.

27. In a shock absorber employingnonresilient means for governing theamount of frictional resistance therein, the combina- 'tion with asupport and a relatively movable friction element, and means to preventseparation of said support and element in operation of the clutch. of anon-circular friction pawl adapted to apply pressure to the frictionelement. the support being provided with a dat surface for thearticulation of said strut.

A shock absorber comprising a triction face, a support and non-resilientmeans for producing pressure upon said face. said means beingconstructed and arranged to produce increased pressure upon movement' ofthe face in one direction only and to re. lieve such increase ofpressure upon cessation of such movement.

29. In a shock absorber. in combination. a brake face. a support, meansto prevent separation of the brake face and support, and a device toeffect frictiona-l resistance on the brake face comprising anon-circular moving strut and articulating seats therefor, said meansbeing constructed and aranged to produce a substantially constant angleof thrustl in the Strut throughout the space provided for the movementof said strut.

30. In a shock absorber of the character set forth, having a contactface, a brake face and a support, a strut having a substantiallyinvolute contact face whereby a constantly increasing rate of separationbetween the brake face and the support throughout the entire allowablemovement of the strut is realized.

31. In a shock absorber, the combination with moving struts of a basehaving radial ways, supports for the struts, an abutment for thesupports, an annulus surrounding 13u lou the ways and rotatable relativeto the ways, means to regulate the space between the annulus and thesupports and non-resilient brake shoes engaging the annulus; said brakeshoes being fitted with rub faces spaced apart on said shoes.

32. In a shock absorber, two relatively rotatable members, radiallymovable nonresilient brake shoes, said shoes being fitted with rub facesspaced apart; and moving strut means operable by relative rotation ofsaid members to move said shoes radially to shoeV titted with aplurality of rub faces' spaced apart at the center ot said shoe andprojecting from the same to take the entire wear on the shoe, the lineot thrust ot the friction pawl on the shoe passing between said faces.

35. In a shock absorber, two relatively rotatable members, radiallymovable nonresilient brake shoes, radially adjustable non-resilientmoving strut means operable by relative rotation oi said members to movesaid shoes radially to frictionally engage one ot said members and meansto adjust said radially adjustable means.

86. A shock absorber comprising two members relatively rotatable about aco1nmon axis, means interposed between said members tor retarding suchrelative rotation in one direction including a brake shoe and anon-circular Jfriction pawl in direct contact therewith, bothnonresilient and transmitting directly the full thrust ot the brake shoeto one of said members, and means to prevent separation of said membersduc to such thrust.

37. In a shock absorber. in combination, two relatively movable butnon-separable members, and means for frictionally retarding the movementof one ot said members relatively to the second, comprising' anonresilient brake shoe and a non-resilient oscillatable strut havingconstant engagement with the brake shoe and said second member,`

the movement of the strut being uncon- 'tined on the resistanceproducing direction.

38. A shock absorber comprising two relatively rotatable members, one ormore nonresilient `floating shoes, non-resilient means operable by therelative rotation of the said members to torce the shoe or shoes intoengagement with one of said members, and j non-resilient means tocontrol said operable means to increase or decrease the force with whichsaid shoe is operated, said means conw sisting otsuch an arrangement ofsuccessive bearing points for said strut as will cause said strut tooperate at a predetermined angle of thrust, substantially as de.scribed.

In testimony whereof, I have hereunto set my hand at Los Angeles,California, this 15th day of July, 191.8.

JAMES PIERCE BALDWIN.

Witness:

JAMES R. TowNsEND.

